1. Field of the Invention
The present invention relates to a steering system for a variable height agricultural sprayer and, more particularly, to an improved steering system for a variable height agricultural sprayer which maintains a predetermined wheel orientation over uneven terrain.
2. Description of the Prior Art
Ride height adjustment systems for agricultural sprayers are known in the art. Such systems typically involve an outer journal provided with an inner leg which rotates relative to the outer journal. In addition to the ride height adjustment, it is also desirable to include a cushioning system to add to driver comfort when operating the agricultural sprayer. A cushioned ride height adjustment system is shown in U.S. Pat. No. 5,597,172.
Prior art suspensions, however, use a large number of large parts, which not only increase the cost and weight of the suspension system, but also the maintenance costs as well. An additional drawback of such prior art suspension systems is that they require a large unobstructed area for proper operation. Prior art suspension systems often utilize a linear actuator coupled to the frame and a scissor assembly which extends beyond the frame of the suspension system. These assemblies require a large unobstructed area which limits their application on more compact agricultural sprayers.
Accordingly, it would be desirable to provide a more compact steering assembly, incorporating fewer, more easily maintained parts. The difficulties encountered hereinabove are sought to be eliminated by the present invention.
The present invention comprises a steering mechanism for a ride height adjustable vehicle comprising a journal, a leg rotatably coupled within the journal, the leg having a first end and a second end, a wheel coupled to the first end of the leg, a base plate secured to the second end of the leg, a spring having a first end and a second end, a first upright having a first end and a second end, wherein the first end of the first upright is secured to the journal, and wherein the second end of the first upright is coupled to the second end of the spring, a second upright substantially parallel with the first upright, the second upright having a first end and a second end, wherein the first end of the second upright is secured to the journal, and wherein the second end of the second upright is coupled to the second end of the spring, a spring plate is secured to the first end of the spring wherein the spring plate is slidably coupled to the first upright, and wherein the spring plate is slidably coupled to the second upright, and means secured to the base plate and to the spring plate for rotating the base plate relative to the spring plate.